This invention relates to gravity outlets used on railway cars to discharge lading and, more particularly, to an improved gravity outlet for use on such cars.
Gravity outlets for use on railroad cars are known in the art. See, for example, U.S. Pat. Nos 4,528,913, 4,036,532, and 3,877,392, which are assigned to the same assignee as the present invention, and which relate to a gravity outlet construction or gate/seal arrangement. The outlets shown in these patents are sliding gate outlets. That is, they have a horizontal plate, or gate, which is moved horizontally back and forth to open and close the outlet. A guide is typically provided to insure proper movement of the gate, prevent binding, etc. Because there is lading resting on top of the closed gate, the force required to open the gate has to overcome this weight. This makes opening of the gate more difficult.
As it moves, the gate bears down on a seal provided to prevent spillage of lading and lading contamination. Contamination occurs when dirt and other contaminants find their way into the compartment where the lading is stored. Over time, the close contact between the gate, its guide, and the seal causes wear. Wear particularly occurs when the gate slides open and there are particles caught between the gate and the seal. This wear, as well as the sealing ability of the seal are also effected by the constant vibration to which the outlet is subjected during movement of the railcar on which the outlet is installed. While removal of the outlet and repair or replacement of parts is not difficult, it is time consuming. Accordingly, the less frequently repairs are needed, the lower the operating costs of the user. It would therefore be advantageous to have a sliding gate outlet in which wear is minimized, but in which the effective functioning of the parts is not impaired.